JPWO2017170945A1 - Liquid crystal aligning agent, liquid crystal aligning film, and liquid crystal display element - Google Patents

Abstract

Ｒ_１、Ｒ_２はそれぞれ独立して、直鎖又は分岐の、炭素数１〜８のアルキル基である。但し、Ｒ_１とＲ_２の合計炭素数はＲ_２は４以上である。Providing a polyimide-based liquid crystal aligning agent suitable for the ink-jet method and a liquid crystal aligning film using the same, which can form a coating film with excellent uniformity of film thickness on the coated surface and excellent linearity and dimensional stability in the coating periphery. To do.
A liquid crystal aligning agent comprising a polymer and a solvent containing a compound represented by the following formula (a).
[Chemical 1]

R _{1 and} R ₂ are each independently a linear or branched alkyl group having 1 to 8 carbon atoms. However, the total number of carbon atoms in _{R 1} and _{R 2 R 2} is 4 or more.

Description

  The present invention relates to a liquid crystal aligning agent suitable for an ink jet film forming method and having high dimensional stability when applied, a liquid crystal aligning film obtained from the liquid crystal aligning agent, and a liquid crystal display device including the liquid crystal aligning film.

As the liquid crystal alignment film, a so-called polyimide-based liquid crystal alignment film, which is obtained by applying and baking a liquid crystal alignment agent mainly composed of a polyimide precursor such as polyamic acid (also called polyamic acid) or a soluble polyimide solution, is widely used. Has been.
Generally, spin coating, dip coating, flexographic printing, and the like are known as film forming methods for such a liquid crystal alignment film. Especially, the application | coating method by flexographic printing has been used until now. However, flexographic printing requires various types of resin plates due to the different types of liquid crystal panels, the plate replacement in the manufacturing process is complicated, and film formation on a dummy substrate is necessary to stabilize the film formation process. There are problems such as the necessity of manufacturing the plate and the production cost of the liquid crystal display panel.

  For this reason, an inkjet method has attracted attention as a method for forming a liquid crystal alignment film without using a printing plate. The ink jet method is a method in which fine droplets are dropped on a substrate and a film is formed by wetting and spreading of the liquid. Not only the printing plate is not used, but also the printing pattern can be set freely, so that the manufacturing process of the liquid crystal display element can be simplified. In addition, there is an advantage that the waste of the coating liquid is reduced because the film formation on the dummy substrate which is necessary for flexographic printing is not necessary. The inkjet method is expected to reduce the cost of liquid crystal panels and improve production efficiency.

The liquid crystal alignment film formed by the ink jet method is required to have small film thickness unevenness inside the coating surface and high film forming accuracy in the peripheral part of the coating. In general, a liquid crystal alignment film formed by an ink-jet method has a trade-off relationship between the uniformity of the film thickness in the coating surface and the film forming accuracy in the periphery of the coating. That is, a material with high in-plane uniformity has low dimensional stability in the periphery of the coating, and the film protrudes from the set dimensions. On the other hand, the material in which the coating peripheral portion is a straight line has low uniformity in the coating surface.
In order to improve the film forming accuracy in the coating peripheral portion, a method of confining the alignment film in a predetermined range with a special structure has been proposed (see Patent Documents 1 to 3). However, these methods have the disadvantage of requiring the use of additional special structures.

Japanese Unexamined Patent Publication No. 2004-361623 Japanese Unexamined Patent Publication No. 2008-145461 Japanese Unexamined Patent Publication No. 2010-281925

  In recent years, with the high definition of liquid crystal display elements, TFT design of multilayer wiring is becoming mainstream. In this design, a contact hole (also referred to as C / H) is formed on the substrate in order to connect the lower layer wiring and the upper layer wiring. Along with this, the spread of the liquid tends to be hindered during the application of the liquid crystal aligning agent due to the influence of the wiring structure and C / H. As a result, unevenness in the thickness of the alignment film, such as dot-like unevenness and streaky unevenness, occurs around the C / H and other portions, and the display on the liquid crystal display element may become uneven.

  In view of the above-described problems, the present invention is capable of suppressing the application failure of the alignment film caused by the influence of the wiring structure and C / H, and the liquid crystal capable of suppressing the failure in which the display of the liquid crystal display element is not uniform. An alignment agent, a liquid crystal alignment film using the alignment agent, and a liquid crystal display device including the liquid crystal alignment film.

式（ａ）中、Ｒ_１、Ｒ_２は、それぞれ独立して、直鎖又は分岐状の炭素数１〜８のアルキル基である。但し、Ｒ_１とＲ_２の炭素数の合計は４以上である。As a result of intensive studies to solve the above problems, the present inventor has completed the present invention.
The gist of the present invention is as described.
1. A liquid crystal aligning agent comprising: a polymer having an ability to align liquid crystals; and a solvent containing a compound represented by the following formula (a).

In formula (a), R _{1 and} R ₂ are each independently a linear or branched alkyl group having 1 to 8 carbon atoms. However, the total number of carbon atoms of R ₁ and R ₂ is 4 or more.

According to the present invention, a polyimide system that can suppress a defective application of a liquid crystal alignment film caused by the influence of a wiring structure or C / H, and can suppress a defect in which display of a liquid crystal display element becomes non-uniform. A liquid crystal aligning agent is obtained.
An object of the present invention is to provide a liquid crystal alignment film using the same and a liquid crystal display element including the liquid crystal alignment film.

<Polymer>
The polymer contained in the liquid crystal aligning agent of this invention will not be specifically limited if it has the capability to align a liquid crystal. The ability to align the liquid crystal is enhanced by aligning the film obtained from the polymer with a rubbing process or ultraviolet irradiation.
Examples of such a polymer include a polyimide precursor, polyimide obtained by imidizing this polyimide precursor, acrylic polymer, methacrylic polymer, acrylamide polymer, methacrylamide polymer, polystyrene, polyvinyl, polysiloxane, polyamide, polyester, polyurethane, Polycarbonate, polyurea, polyphenol (novolak resin), maleimide polymer, and a polymer in which a compound having an isocyanuric acid skeleton or a triazine skeleton is introduced.
The polymer may be in the form of a branched polymer such as a dendrimer, a hyperbranched polymer or a star-like polymer, or a non-covalent polymer such as polycatenan or polyrotaxane.

The following are mentioned as a monomer for manufacturing these polymers.
When the polymer is a polyimide precursor such as polyamic acid or polyamic acid ester or polyimide, at least one tetracarboxylic acid component selected from tetracarboxylic acid or a derivative thereof and a diamine component; when the polymer is an acrylic polymer, acrylic Acid or derivative thereof, acrylic ester or derivative thereof; when the polymer is methacrylic polymer, methacrylic acid or derivative thereof, methacrylic ester or derivative thereof; when polymer is acrylamide polymer, acrylamide or derivative thereof; In the case of a methacrylamide polymer, methacrylamide or a derivative thereof; when the polymer is polystyrene, styrene or a derivative thereof; when the polymer is polyvinyl, a derivative having a vinyl group; In the case of siloxane, a silane compound having a methoxy group or an ethoxy group; in the case where the polymer is a polyamide, at least one dicarboxylic acid component selected from dicarboxylic acid and derivatives thereof and a diamine component; in the case where the polymer is a polyester, a dicarboxylic acid At least one dicarboxylic acid component and diol component selected from acids and derivatives thereof; when the polymer is polyurethane, a compound having an isocyanate, a compound and a hydroxyl group; when the polymer is polycarbonate, a bisphenol derivative and phosgene or phosgene An equivalent (for example, trichlorophosgene) or diphenyl carbonate; when the polymer is polyurea, a bisisocyanate derivative and a diamine component; when the polymer is a maleimide polymer, copolymerization with the maleimide derivative alone or with styrene; Coalescence case of a polymer obtained by introducing a compound having an isocyanuric acid skeleton and a triazine skeleton include compounds having an isocyanuric acid skeleton and a triazine skeleton.

The polymer or the monomer for producing the polymer may be one kind or a combination of two or more kinds. The polyimide precursor is
Among these, from the viewpoint of practicality as a liquid crystal aligning agent and mechanical and electrical properties of the coating film, at least one polymer selected from a polyimide precursor and a polyimide obtained by imidizing this polyimide precursor ( Hereinafter, it is also referred to as a specific polymer).
The polymer which the liquid crystal aligning agent of this invention contains can be manufactured by the method currently performed normally. For example, a polyimide precursor that is a specific polymer is obtained by polymerizing a tetracarboxylic acid derivative component composed of tetracarboxylic acid or a derivative thereof and a diamine component as described above, and imidizes the polyimide precursor. As a result, polyimide is obtained.

式（ａ）中、Ｒ_１、Ｒ_２は，それぞれ独立して、直鎖又は分岐状の炭素数１〜８、好ましくは３〜８、より好ましくは３〜６のアルキル基である。但し、Ｒ_１及びＲ_２の炭素数の合計は４以上であり、好ましくは５〜１２である。<Specific solvent>
The liquid crystal aligning agent of this invention contains the solvent containing the solvent (henceforth a specific solvent) consisting of the compound represented by a following formula (a).

In the formula (a), R _{1 and} R ₂ are each independently a linear or branched alkyl group having 1 to 8, preferably 3 to 8, more preferably 3 to 6 carbon atoms. However, the total carbon number of R ₁ and R ₂ is 4 or more, preferably 5-12.

Specific examples of the specific solvent include, but are not limited to, the following a-1 to a-48.

Among these, from the viewpoints of availability and practicality, a-22, a-13 to a-21, a-24, a-26, a-27, a-31, a-34, a-37, or a -38 is preferable and a-22 or a-37 is more preferable.
In the liquid crystal aligning agent of the present invention, the content of the specific solvent is preferably 1 to 50% by mass or less, more preferably 1 to 30% by mass, and still more preferably 1 to 20% by mass with respect to the weight of the total solvent.

<Specific polymer>
It is preferable that the polyimide precursor which is a specific polymer contained in the liquid crystal aligning agent of this invention has a structure represented by the following formula | equation (1).

In the above formula (1), X ₁ is a tetravalent organic group derived from a tetracarboxylic acid derivative, Y ₁ is a divalent organic group derived from a diamine, and R ₁ is a hydrogen atom or a carbon atom number of 1 Represents an alkylene of ~ 5. From the viewpoint of easy progress of the imidization reaction during heating, R ₁ is preferably a hydrogen atom, a methyl group, or an ethyl group, and more preferably a hydrogen atom or a methyl group.
A ₁ and A ₂ are each independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 2 to 5 carbon atoms, or an alkynyl group having 2 to 5 carbon atoms. From the viewpoint of liquid crystal orientation, A ₁ and A ₂ are preferably a hydrogen atom or a methyl group.

Below, each component used as the raw material which manufactures the said polyimide precursor is demonstrated.
<Diamine>
Although the diamine component used for manufacture of a polyimide precursor is not specifically limited, The diamine which is a raw material of the polyimide precursor represented by the said Formula (1) is represented by following formula (2).

In the above formula (2), A ₁ and A ₂ are the same definition as A ₁ and A ₂ in the above formula (1), including preferred examples. To illustrate the Y _1, include the following (Y-1) ~ (Y -170). It is as follows.

式中、ｎは、１〜６の整数であり、Ｍｅはメチル基である。

In the formula, n is an integer of 1 to 6, and Me is a methyl group.

Among them, _{Y 1} is, (Y-7), ( Y-8), (Y-16), (Y-17), (Y-18), (Y-20), (Y-21), (Y-22), (Y-28), (Y-35), (Y-38), (Y-43), (Y-48), (Y-64), (Y-66), (Y -71), (Y-72), (Y-76), (Y-77), (Y-80), (Y-81), (Y-82), (Y-83), (Y156), (Y-159), (Y-160), (Y-161), (Y-162) (Y-168), (Y-169), or (Y-170) is preferred. In particular, (Y-7), (Y-8), (Y-16), (Y-17), (Y-18), (Y-21), (Y-22), (Y-28) , (Y-38), (Y-64), (Y-66), (Y-72), (Y-76), (Y-81), (Y156), (Y-159), (Y- 160), (Y-161), (Y-162) (Y-168), (Y-169), or (Y-170) is preferred.

<Tetracarboxylic acid derivative>
Although the tetracarboxylic acid derivative used for manufacture of a polyimide precursor is not specifically limited, As a tetracarboxylic acid derivative component which is a raw material of the polyimide precursor represented by the above formula (1), only tetracarboxylic dianhydride is used. The derivatives thereof include tetracarboxylic acid, tetracarboxylic acid dihalide, tetracarboxylic acid dialkyl ester, and tetracarboxylic acid dialkyl ester dihalide.
As the tetracarboxylic dianhydride or a derivative thereof, it is more preferable to use a tetracarboxylic dianhydride or a derivative thereof represented by the following formula (3).

式（３）中、Ｘ_１は、脂環式構造を有する４価の有機基であり、その構造は特に限定されない。具体例としては、下記式（Ｘ１−１）〜（Ｘ１−４４）が挙げられる。

In Formula (3), X ₁ is a tetravalent organic group having an alicyclic structure, and the structure is not particularly limited. Specific examples include the following formulas (X1-1) to (X1-44).

In the above formulas (X1-1) to (X1-4), R _{3 to} R ₂₃ are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkenyl group having 2 to 6 carbon atoms. , An alkynyl group having 2 to 6 carbon atoms, a monovalent organic group having 1 to 6 carbon atoms containing a fluorine atom, or a phenyl group. From the viewpoint of liquid crystal orientation, R _{3 to} R ₂₃ are preferably a hydrogen atom, a halogen atom, a methyl group, or an ethyl group, and more preferably a hydrogen atom or a methyl group.

Specific examples of the formula (X1-1) include the following formulas (X1-1-1) to (X1-1-6). (X1-1-1) is particularly preferable from the viewpoint of liquid crystal alignment and photoreaction sensitivity.

  The tetracarboxylic dianhydride or derivative thereof, which is the raw material of the polyimide precursor and polyimide of the present invention, is tetra represented by the above formula (3) with respect to 1 mol of all tetracarboxylic dianhydride or derivative thereof. It is preferable to contain 60-100 mol% of carboxylic dianhydrides or derivatives thereof. Since the liquid crystal aligning film which has favorable liquid crystal aligning property is obtained, 80-100 mol% is more preferable, and 90-100 mol% is further more preferable.

<Polyimide precursor>
<Method for producing polyamic acid ester>
The polyamic acid ester which is one of the polyimide precursors used for this invention can be manufactured by the method of (1), (2) or (3) shown below.
(1) When manufacturing from polyamic acid A polyamic acid ester is compoundable by esterifying the polyamic acid obtained from tetracarboxylic dianhydride and diamine.
Specifically, the polyamic acid and the esterifying agent are reacted in the presence of an organic solvent at −20 ° C. to 150 ° C., preferably 0 ° C. to 50 ° C., for 30 minutes to 24 hours, preferably 1 to 4 hours. Can be manufactured.

  As the esterifying agent, those that can be easily removed by purification are preferred, and N, N-dimethylformamide dimethyl acetal, N, N-dimethylformamide diethyl acetal, N, N-dimethylformamide dipropyl acetal, N, N-dimethylformamide Dineopentyl butyl acetal, N, N-dimethylformamide di-t-butyl acetal, 1-methyl-3-p-tolyltriazene, 1-ethyl-3-p-tolyltriazene, 1-propyl-3-p -Tolyltriazene, 4- (4,6-dimethoxy-1,3,5-triazin-2-yl) -4-methylmorpholinium chloride and the like. The amount of the esterifying agent used is preferably 2 to 6 molar equivalents per 1 mol of the polyamic acid repeating unit.

  The solvent used in the above reaction is preferably N, N-dimethylformamide, N-methyl-2-pyrrolidone, or γ-butyrolactone from the solubility of the polymer, and these may be used alone or in combination of two or more. Good. The concentration of the polymer in the reaction solution is preferably 1 to 30% by mass and more preferably 5 to 20% by mass from the viewpoint that polymer precipitation is unlikely to occur and a high molecular weight body is easily obtained.

(2) When manufacturing by reaction of tetracarboxylic-acid diester dichloride and diamine Polyamic acid ester can be manufactured from tetracarboxylic-acid diester dichloride and diamine.
Specifically, tetracarboxylic acid diester dichloride and diamine in the presence of a base and an organic solvent are −20 ° C. to 150 ° C., preferably 0 ° C. to 50 ° C., 30 minutes to 24 hours, preferably 1 to 4 hours. It can be synthesized by reacting.
As the base, pyridine, triethylamine, 4-dimethylaminopyridine and the like can be used, but pyridine is preferable because the reaction proceeds gently. The amount of the base used is preferably 2 to 4 times the mol of the tetracarboxylic acid diester dichloride from the viewpoint of easy removal and high molecular weight.

  The solvent used in the above reaction is preferably N-methyl-2-pyrrolidone or γ-butyrolactone from the solubility of the monomer and polymer, and these may be used alone or in combination of two or more. The polymer concentration in the reaction solution is preferably 1 to 30% by mass and more preferably 5 to 20% by mass from the viewpoint that polymer precipitation is unlikely to occur and a high molecular weight body is easily obtained. In order to prevent hydrolysis of the tetracarboxylic acid diester dichloride, the solvent used for the synthesis of the polyamic acid ester is preferably dehydrated as much as possible, and it is preferable to prevent mixing of outside air in a nitrogen atmosphere.

(3) When manufacturing polyamic acid ester from tetracarboxylic-acid diester and diamine Polyamic-acid ester can be jointly manufactured by polycondensing tetracarboxylic-acid diester and diamine.
Specifically, tetracarboxylic acid diester and diamine in the presence of a condensing agent, a base, and an organic solvent are 0 ° C to 150 ° C, preferably 0 ° C to 100 ° C, 30 minutes to 24 hours, preferably 3 to 15 hours. It can be produced by reacting for a period of time.

Examples of the condensing agent include triphenyl phosphite, dicyclohexylcarbodiimide, 1-ethyl-3- (3-dimethylaminopropyl) carbodiimide hydrochloride, N, N′-carbonyldiimidazole, dimethoxy-1,3,5-triazi Nylmethylmorpholinium, O- (benzotriazol-1-yl) -N, N, N ′, N′-tetramethyluronium tetrafluoroborate, O- (benzotriazol-1-yl) -N, N , N ′, N′-tetramethyluronium hexafluorophosphate, diphenyl (2,3-dihydro-2-thioxo-3-benzoxazolyl) phosphonate, and the like. As for the addition amount of a condensing agent, 2-3 times mole is preferable with respect to tetracarboxylic-acid diester.
As the base, tertiary amines such as pyridine and triethylamine can be used. The amount of the base used is preferably 2 to 4 moles with respect to the diamine component from the viewpoint that it can be easily removed and a high molecular weight product can be easily obtained.

In the above reaction, the reaction proceeds efficiently by adding Lewis acid as an additive. As the Lewis acid, lithium halides such as lithium chloride and lithium bromide are preferable. The addition amount of the Lewis acid is preferably 0 to 1.0 times the mole of the diamine component.
Among the methods for synthesizing the three polyamic acid esters, since a high molecular weight polyamic acid ester is obtained, the synthesis method (1) or (2) is particularly preferable.
The polyamic acid ester solution obtained as described above can be polymerized by pouring into a poor solvent while stirring well. Precipitation is performed several times, and after washing with a poor solvent, a purified polyamic acid ester powder can be obtained at room temperature or by heating and drying. Although a poor solvent is not specifically limited, Water, methanol, ethanol, hexane, butyl cellosolve, acetone, toluene etc. are mentioned.

<Method for producing polyamic acid>
The polyamic acid which is a polyimide precursor used in the present invention can be produced by the following method.
Specifically, tetracarboxylic dianhydride and diamine are reacted in the presence of an organic solvent at −20 ° C. to 150 ° C., preferably 0 ° C. to 50 ° C. for 30 minutes to 24 hours, preferably 1 to 12 hours. Can be synthesized.
The organic solvent used in the above reaction is preferably N, N-dimethylformamide, N-methyl-2-pyrrolidone, or γ-butyrolactone from the solubility of the monomer and the polymer, and these may be used alone or in combination of two or more. It may be used. The concentration of the polymer is preferably 1 to 30% by mass and more preferably 5 to 20% by mass from the viewpoint that the polymer is hardly precipitated and a high molecular weight body is easily obtained.

  The polyamic acid obtained as described above can be recovered by precipitating the polymer by pouring into the poor solvent while thoroughly stirring the reaction solution. Moreover, the powder of polyamic acid refine | purified by performing precipitation several times, washing | cleaning with a poor solvent, and normal temperature or heat-drying can be obtained. Although a poor solvent is not specifically limited, Water, methanol, ethanol, hexane, butyl cellosolve, acetone, toluene etc. are mentioned.

<Production method of polyimide>
The polyimide used in the present invention can be produced by imidizing the polyamic acid ester or polyamic acid. When a polyimide is produced from a polyamic acid ester, chemical imidization in which a basic catalyst is added to a polyamic acid solution obtained by dissolving the polyamic acid ester solution or the polyamic acid ester resin powder in an organic solvent is simple. Chemical imidization is preferable because the imidization reaction proceeds at a relatively low temperature and the molecular weight of the polymer does not easily decrease during the imidization process.

  Chemical imidation can be performed by stirring the polyamic acid ester to be imidized in an organic solvent in the presence of a basic catalyst. As an organic solvent, the solvent used at the time of the polymerization reaction mentioned above can be used. Examples of the basic catalyst include pyridine, triethylamine, trimethylamine, tributylamine, trioctylamine and the like. Of these, triethylamine is preferred because it has sufficient basicity to allow the reaction to proceed.

  The temperature at which the imidization reaction is performed is -20 ° C to 140 ° C, preferably 0 ° C to 100 ° C, and the reaction time can be 1 to 100 hours. The amount of the basic catalyst is 0.5 to 30 moles, preferably 2 to 20 moles, of the amic acid ester group. The imidation ratio of the resulting polymer can be controlled by adjusting the amount of catalyst, temperature, and reaction time. Since the added catalyst or the like remains in the solution after the imidation reaction, the obtained imidized polymer is preferably recovered and redissolved in an organic solvent to obtain the liquid crystal aligning agent of the present invention. .

When manufacturing a polyimide from a polyamic acid, chemical imidation which adds a catalyst to the solution of the said polyamic acid obtained by reaction with a diamine component and tetracarboxylic dianhydride is simple. Chemical imidization is preferable because the imidization reaction proceeds at a relatively low temperature and the molecular weight of the polymer is unlikely to decrease during the imidization process.
Chemical imidation can be performed by stirring a polymer to be imidized in an organic solvent in the presence of a basic catalyst and an acid anhydride. As an organic solvent, the solvent used at the time of the polymerization reaction mentioned above can be used. Examples of the basic catalyst include pyridine, triethylamine, trimethylamine, tributylamine, trioctylamine and the like. Of these, pyridine is preferable because it has an appropriate basicity for proceeding with the reaction. Examples of the acid anhydride include acetic anhydride, trimellitic anhydride, pyromellitic anhydride and the like. Among them, use of acetic anhydride is preferable because purification after completion of the reaction is facilitated.

The temperature at which the imidization reaction is performed is -20 ° C to 140 ° C, preferably 0 ° C to 100 ° C, and the reaction time can be 1 to 100 hours. The amount of the basic catalyst is 0.5 to 30 mol times, preferably 2 to 20 mol times of the amic acid group, and the amount of the acid anhydride is 1 to 50 mol times, preferably 3 to 30 mol of the amic acid group. Is double. The imidation ratio of the resulting polymer can be controlled by adjusting the amount of catalyst, temperature, and reaction time.
In the solution after the imidation reaction of polyamic acid ester or polyamic acid, the added catalyst and the like remain, so the obtained imidized polymer is recovered by the means described below, and redissolved in an organic solvent. Thus, the liquid crystal aligning agent of the present invention is preferable.

The polyimide solution obtained as described above can be polymerized by pouring into a poor solvent while stirring well. Precipitation is performed several times, and after washing with a poor solvent, a purified polyamic acid ester powder can be obtained at room temperature or by heating and drying.
The poor solvent is not particularly limited, and examples thereof include methanol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, and benzene.

<Liquid crystal aligning agent>
The liquid crystal aligning agent of this invention has the form of the solution in which the polymer containing a specific polymer was melt | dissolved in the solvent containing a specific solvent. The molecular weight of the polymer including the specific polymer is preferably 2,000 to 500,000 in terms of weight average molecular weight, more preferably 5,000 to 300,000, and still more preferably 10,000 to 100,000. is there. The number average molecular weight is preferably 1,000 to 250,000, more preferably 2,500 to 150,000, and still more preferably 5,000 to 50,000.
The concentration of the polymer containing the specific polymer used in the present invention can be appropriately changed according to the setting of the thickness of the coating film to be formed, but it is 1% by weight or more from the viewpoint of forming a uniform and defect-free coating film. From the viewpoint of storage stability of the solution, it is preferably 10% by weight or less.

<Other solvents>
The solvent used for the liquid crystal aligning agent of the present invention can contain a solvent other than the specific solvent described above (hereinafter also referred to as other solvent). Other solvents are preferred. The solvent is not particularly limited as long as it is a solvent (also referred to as a good solvent) that dissolves the polymer described in the present invention. Although the specific example of a good solvent is given to the following, it is not limited to these examples.
For example, N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, dimethyl sulfoxide, γ-butyrolactone, 1,3-dimethyl-imidazolidinone, methyl ethyl ketone , Cyclohexanone, cyclopentanone, 3-methoxy-N, N-dimethylpropanamide or 4-hydroxy-4-methyl-2-pentanone.
Of these, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, γ-butyrolactone, 3-methoxy-N, N-dimethylpropanamide, or 1,3-dimethyl-2-imidazolidinone is preferable.
Such a good solvent is preferably contained in an amount of 20 to 99% by weight, more preferably 30 to 80% by weight based on the total amount of the solvent.

（式［Ｄ−１］中、Ｄ^１は炭素数１〜３のアルキル基を示し、式［Ｄ−２］中、Ｄ^２は炭素数１〜３のアルキル基を示し、式［Ｄ−３］中、Ｄ^３は炭素数１〜４のアルキル基を示す）。Furthermore, when the solubility to the solvent of the polyimide precursor and polyimide as described in this invention is high, it is preferable to use the solvent shown by following formula [D-1]-a formula [D-3].

(In the formula [D-1], D ¹ represents an alkyl group having 1 to 3 carbon atoms, and in the formula [D-2], D ² represents an alkyl group having 1 to 3 carbon atoms, and the formula [D-3 ], D < ³ > shows a C1-C4 alkyl group.

  As another solvent, the solvent (it is also called a poor solvent) which improves the coating property and surface smoothness of a liquid crystal aligning film at the time of apply | coating a liquid crystal aligning agent can be contained. These poor solvents are preferably 1 to 80% by mass of the entire solvent contained in the liquid crystal aligning agent. Especially, 10-80 mass% is preferable. More preferred is 20 to 70% by mass.

Although the specific example of a poor solvent is given to the following, it is not limited to these examples. For example, ethanol, isopropyl alcohol, 1-butanol, 2-butanol, isobutyl alcohol, tert-butyl alcohol, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, isopentyl alcohol, tert-pentyl alcohol, 3-methyl-2-butanol, neopentyl alcohol, 1-hexanol, 2-methyl-1-pentanol, 2-methyl-2-pentanol, 2-ethyl-1-butanol, 1-heptanol 2-heptanol, 3-heptanol, 1-octanol, 2-octanol, 2-ethyl-1-hexanol, cyclohexanol, 1-methylcyclohexanol, 2-methylcyclohexanol, 3-methylcyclohexanol, 1,2- Etanji 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,5-pentane Diol, 2-methyl-2,4-pentanediol, 2-ethyl-1,3-hexanediol, dipropyl ether, dibutyl ether, dihexyl ether, dioxane, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, 1,2-butoxyethane, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol dibutyl ether, 2-pentanone, 3-pentanone, 2-hexanone, 2 Heptanone, 4-heptanone, 3-ethoxybutyl acetate, 1-methylpentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, ethylene glycol monoacetate, ethylene glycol diacetate, propylene carbonate, ethylene carbonate 2- (methoxymethoxy) ethanol, butyl cellosolve, ethylene glycol monoisoamyl ether, ethylene glycol monohexyl ether, 2- (hexyloxy) ethanol, furfuryl alcohol, diethylene glycol, propylene glycol, 1-butoxy-2-propanol, 1- (Butoxyethoxy) propanol, propylene glycol monomethyl ether acetate, dipropylene glycol, dipropylene glycol monomer Chill ether, dipropylene glycol monoethyl ether, dipropylene glycol dimethyl ether, tripropylene glycol monomethyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, butyl cellosolve acetate, ethylene glycol monoacetate, ethylene glycol diacetate , Diethylene glycol monoethyl ether acetate, diacetone alcohol, propylene glycol diacetate, diisopentyl ether, diethylene glycol monobutyl ether acetate, 2- (2-ethoxyethoxy) ethyl acetate, diethylene glycol acetate, triethylene glycol, triethylene glycol Ethylene glycol monomethyl ether, triethyl Glycol monoethyl ether, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether acetate, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, methyl 3-ethoxypropionate Ethyl, ethyl 3-methoxypropionate, 3-ethoxypropionic acid, 3-methoxypropionic acid, propyl 3-methoxypropionate, butyl 3-methoxypropionate, methyl lactate, ethyl lactate, n-propyl lactate, lactic acid Examples thereof include n-butyl ester, isoamyl lactate, diisobutyl ketone, ethyl carbitol, and solvents represented by the above formulas [D-1] to [D-3].
Among them, butyl cellosolve, 1-butoxy-2-propanol, butyl cellosolve acetate, dipropylene glycol monomethyl ether, diacetone alcohol, diethylene glycol diethyl ether, diisopentyl ether, propylene glycol diacetate, diisobutyl ketone, ethyl carbitol or dithiol It is preferable to use propylene glycol dimethyl ether.

  The liquid crystal aligning agent of the present invention includes at least one substituent selected from the group consisting of a crosslinkable compound having an epoxy group, an isocyanate group, an oxetane group or a cyclocarbonate group, a hydroxyl group, a hydroxyalkyl group and a lower alkoxyalkyl group. Or a crosslinkable compound having a polymerizable unsaturated bond. It is necessary to have two or more of these substituents and polymerizable unsaturated bonds in the crosslinkable compound.

  Examples of the crosslinkable compound having an epoxy group or an isocyanate group include bisphenolacetone glycidyl ether, phenol novolac epoxy resin, cresol novolac epoxy resin, triglycidyl isocyanurate, tetraglycidylaminodiphenylene, tetraglycidyl-m-xylenediamine, tetra Glycidyl-1,3-bis (aminoethyl) cyclohexane, tetraphenyl glycidyl ether ethane, triphenyl glycidyl ether ethane, bisphenol hexafluoroacetodiglycidyl ether, 1,3-bis (1- (2,3-epoxypropoxy)- 1-trifluoromethyl-2,2,2-trifluoromethyl) benzene, 4,4-bis (2,3-epoxypropoxy) octafluorobiphenyl, Liglycidyl-p-aminophenol, tetraglycidylmetaxylenediamine, 2- (4- (2,3-epoxypropoxy) phenyl) -2- (4- (1,1-bis (4- (2,3-epoxy) Propoxy) phenyl) ethyl) phenyl) propane or 1,3-bis (4- (1- (4- (2,3-epoxypropoxy) phenyl) -1- (4- (1- (4- (2,3 -Epoxypropoxy) phenyl) -1-methylethyl) phenyl) ethyl) phenoxy) -2-propanol and the like.

具体的には、国際公開公報ＷＯ２０１１／１３２７５１号（２０１１．１０．２７公開）の５８〜５９頁に掲載される式［４ａ］〜式［４ｋ］で示される架橋性化合物が挙げられる。The crosslinkable compound having an oxetane group is a compound having at least two oxetane groups represented by the following formula [4A].

Specific examples include crosslinkable compounds represented by the formulas [4a] to [4k] published on pages 58 to 59 of International Publication No. WO2011 / 132751 (published 2011.10.27).

具体的には、国際公開公報ＷＯ２０１２／０１４８９８号（２０１２．２．２公開）の７６〜８２頁に掲載される式［５−１］〜式［５−４２］で示される架橋性化合物が挙げられる。The crosslinkable compound having a cyclocarbonate group is a crosslinkable compound having at least two cyclocarbonate groups represented by the following formula [5A].

Specifically, the crosslinkable compounds represented by the formulas [5-1] to [5-42] described on pages 76 to 82 of International Publication No. WO2012 / 014898 (published 2012.2.2). It is done.

  Examples of the crosslinkable compound having at least one substituent selected from the group consisting of a hydroxyl group and an alkoxyl group include an amino resin having a hydroxyl group or an alkoxyl group, such as a melamine resin, a urea resin, a guanamine resin, and a glycoluril. -Formaldehyde resin, succinylamide-formaldehyde resin or ethylene urea-formaldehyde resin. Specifically, a melamine derivative, a benzoguanamine derivative, or glycoluril in which a hydrogen atom of an amino group is substituted with a methylol group, an alkoxymethyl group, or both can be used. The melamine derivative or benzoguanamine derivative can exist as a dimer or a trimer. These preferably have an average of 3 to 6 methylol groups or alkoxymethyl groups per triazine ring.

  Examples of the melamine derivative or benzoguanamine derivative include MX-750 in which an average of 3.7 methoxymethyl groups are substituted per one triazine ring, and an average of 5.8 methoxymethyl groups per one triazine ring. Individually substituted MW-30 (manufactured by Sanwa Chemical Co., Ltd.) and Cymel 300, 301, 303, 350, 370, 771, 325, 327, 703, 712 and other methoxymethylated melamines, Cymel 235, 236, Methoxymethylated butoxymethylated melamine such as 238, 212, 253, 254, butoxymethylated melamine such as Cymel 506, 508, carboxyl group-containing methoxymethylated isobutoxymethylated melamine such as Cymel 1141, methoxymethyl such as Cymel 1123 Ethoxymethylation Nzoguanamine, methoxymethylated butoxymethylated benzoguanamine such as Cymel 1123-10, butoxymethylated benzoguanamine such as Cymel 1128, carboxyl group-containing methoxymethylated ethoxymethylated benzoguanamine such as Cymel 1125-80 (manufactured by Mitsui Cyanamid Co., Ltd.) Can be mentioned. Examples of glycoluril include butoxymethylated glycoluril such as Cymel 1170, methylolated glycoluril such as Cymel 1172, methoxymethylolated glycoluril such as Powderlink 1174, and the like.

Examples of the benzene or phenolic compound having a hydroxyl group or an alkoxyl group include 1,3,5-tris (methoxymethyl) benzene, 1,2,4-tris (isopropoxymethyl) benzene, 1,4-bis ( sec-butoxymethyl) benzene or 2,6-dihydroxymethyl-p-tert-butylphenol.
More specifically, crosslinkable compounds of the formulas [6-1] to [6-48], which are listed on pages 62 to 66 of International Publication No. WO2011 / 132751 (2011.10.27 publication). It is done.

  Examples of the crosslinkable compound having a polymerizable unsaturated bond include trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, and tri (meth) acryloyloxyethoxytrimethylol. Crosslinkable compounds having three polymerizable unsaturated groups in the molecule such as propane or glycerin polyglycidyl ether poly (meth) acrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, tetraethylene glycol di (Meth) acrylate, polyethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, butylene glycol Di (meth) acrylate, neopentyl glycol di (meth) acrylate, ethylene oxide bisphenol A type di (meth) acrylate, propylene oxide bisphenol type di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, glycerin Di (meth) acrylate, pentaerythritol di (meth) acrylate, ethylene glycol diglycidyl ether di (meth) acrylate, diethylene glycol diglycidyl ether di (meth) acrylate, diglycidyl phthalate di (meth) acrylate or hydroxypivalic acid neo A crosslinkable compound having two polymerizable unsaturated groups in the molecule, such as pentyl glycol di (meth) acrylate, in addition, 2-hydroxyethyl (meth) acrylate, -Hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2-phenoxy-2-hydroxypropyl (meth) acrylate, 2- (meth) acryloyloxy-2-hydroxypropyl phthalate, 3-chloro-2- Crosslinkable compound having one polymerizable unsaturated group in the molecule such as hydroxypropyl (meth) acrylate, glycerin mono (meth) acrylate, 2- (meth) acryloyloxyethyl phosphate ester or N-methylol (meth) acrylamide Etc.

（式［７Ａ］中、Ｅ_１はシクロヘキサン環、ビシクロヘキサン環、ベンゼン環、ビフェニル環、ターフェニル環、ナフタレン環、フルオレン環、アントラセン環又はフェナントレン環からからなる群から選ばれる基を示し、Ｅ_２は下記式［７ａ］又は式［７ｂ］から選ばれる基を示し、ｎは１〜４の整数を示す）。

Furthermore, a compound represented by the following formula [7A] can also be used.

(In the formula [7A], E ₁ represents a group selected from the group consisting of a cyclohexane ring, a bicyclohexane ring, a benzene ring, a biphenyl ring, a terphenyl ring, a naphthalene ring, a fluorene ring, an anthracene ring or a phenanthrene ring; ₂ represents a group selected from the following formula [7a] or [7b], and n represents an integer of 1 to 4.

Moreover, the crosslinkable compound used for the liquid crystal aligning agent of this invention may be 1 type, or may combine 2 or more types.
As for content of a crosslinkable compound in the liquid crystal aligning agent of this invention, 0.1-150 mass parts is preferable with respect to 100 mass parts of all the polymer components. Especially, 0.1-100 mass parts is preferable in order for a crosslinking reaction to advance and to express the target effect. More preferred is 1 to 50 parts by mass.

The liquid crystal aligning agent of this invention can contain the compound which improves the uniformity and the surface smoothness of the film thickness of the liquid crystal aligning film at the time of apply | coating a liquid crystal aligning agent.
Examples of the compound that improves the film thickness uniformity and surface smoothness of the liquid crystal alignment film include fluorine-based surfactants, silicone-based surfactants, and nonionic surfactants.
More specifically, for example, F-top EF301, EF303, EF352 (above, manufactured by Tochem Products), MegaFuck F171, F173, R-30 (above, manufactured by Dainippon Ink), Florard FC430, FC431 (or more) And Asahi Guard AG710, Surflon S-382, SC101, SC102, SC103, SC104, SC105, SC106 (above, manufactured by Asahi Glass Co., Ltd.) and the like.

The amount of the surfactant used is preferably 0.01 to 2 parts by mass, more preferably 0.01 to 1 part by mass with respect to 100 parts by mass of all the polymer components contained in the liquid crystal aligning agent.
Furthermore, as a compound that promotes charge transfer in the liquid crystal alignment film and promotes charge release of the device, the liquid crystal aligning agent is disclosed in International Publication No. WO2011 / 132751 (published 2011.10.27), pages 69-73. Nitrogen-containing heterocyclic amines represented by the formulas [M1] to [M156] can be added. The amine may be added directly to the liquid crystal aligning agent, but it is preferable to add the amine after forming a solution having a concentration of 0.1 to 10% by mass, preferably 1 to 7% by mass. The solvent is not particularly limited as long as the specific polymer is dissolved.

  The liquid crystal aligning agent of the present invention includes a liquid crystal in addition to the above poor solvent, crosslinkable compound, resin film or compound that improves the film thickness uniformity and surface smoothness of the liquid crystal alignment film, and a compound that promotes charge removal. Add a silane coupling agent for the purpose of improving the adhesion between the alignment film and the substrate, and an imidization accelerator for the purpose of efficiently advancing imidization by heating the polyimide precursor when the coating film is baked. May be.

<Liquid crystal alignment film and liquid crystal display element>
The liquid crystal alignment film of the present invention is a film obtained by applying the above liquid crystal aligning agent to a substrate, drying and baking. The substrate to which the liquid crystal aligning agent of the present invention is applied is not particularly limited as long as it is a highly transparent substrate, and a glass substrate, a silicon nitride substrate, a plastic substrate such as an acrylic substrate or a polycarbonate substrate, or the like can also be used. At that time, it is preferable to use a substrate on which an ITO electrode or the like for driving the liquid crystal is used in terms of simplification of the process. In the reflective liquid crystal display element, an opaque material such as a silicon wafer can be used as long as it is only on one side of the substrate, and a material that reflects light such as aluminum can be used for the electrode in this case.

The film forming method of the liquid crystal aligning agent is industrially generally performed by screen printing, offset printing, flexographic printing, an inkjet method, or the like. As other film forming and coating methods, a dip method, a roll coater method, a slit coater method, a spinner method, a spray method, and the like are known.
Among them, the liquid crystal aligning agent of the present invention can reduce the viscosity of the liquid crystal aligning agent while maintaining a high content ratio of the polymer and the molecular weight of the polymer as described above. Can be suitably used.

  After the liquid crystal aligning agent is applied onto the substrate, the solvent can be evaporated by a heating means such as a hot plate, a thermal circulation oven, or an IR (infrared) oven to form a liquid crystal alignment film. Arbitrary temperature and time can be selected for the drying and baking steps after applying the liquid crystal aligning agent. Usually, in order to fully remove the contained solvent, the condition of baking at 50 to 120 ° C. for 1 to 10 minutes and then baking at 150 to 300 ° C. for 5 to 120 minutes can be mentioned. Since the reliability of a liquid crystal display element may fall when the thickness of the liquid crystal aligning film after baking is too thin, 5-300 nm is preferable and 10-200 nm is more preferable.

The liquid crystal aligning agent of the present invention can be used as a liquid crystal alignment film without applying an alignment treatment in a vertical alignment application or the like after being applied and baked on a substrate and then subjected to an alignment treatment by a rubbing treatment or a photo-alignment treatment. . In the alignment treatment such as rubbing treatment or photo-alignment treatment, a known method or apparatus can be used.
As an example of a method for manufacturing a liquid crystal cell, a liquid crystal display element having a passive matrix structure will be described as an example. Note that an active matrix liquid crystal display element in which a switching element such as a TFT (Thin Film Transistor) is provided in each pixel portion constituting the image display may be used.

Specifically, a transparent glass substrate is prepared, a common electrode is provided on one substrate, and a segment electrode is provided on the other substrate. These electrodes can be ITO electrodes, for example, and are patterned so as to display a desired image. Next, an insulating film is provided on each substrate so as to cover the common electrode and the segment electrode. The insulating film can be, for example, a SiO ₂ —TiO ₂ film formed by a sol-gel method.

  Next, a liquid crystal alignment film is formed on each substrate, the other substrate is overlaid on one substrate so that the liquid crystal alignment film faces each other, and the periphery is bonded with a sealant. In order to control the substrate gap, a spacer is usually mixed in the sealant, and it is preferable to spray a spacer for controlling the substrate gap on the in-plane portion where no sealant is provided. A part of the sealant is provided with an opening that can be filled with liquid crystal from the outside. Next, a liquid crystal material is injected into the space surrounded by the two substrates and the sealing agent through the opening provided in the sealing agent, and then the opening is sealed with an adhesive. For the injection, a vacuum injection method may be used, or a method utilizing capillary action in the atmosphere may be used. As the liquid crystal material, either a positive liquid crystal material or a negative liquid crystal material may be used, but a negative liquid crystal material is preferable. Next, a polarizing plate is installed. Specifically, a pair of polarizing plates is attached to the surfaces of the two substrates opposite to the liquid crystal layer.

The present invention will be described in more detail with reference to examples below, but the present invention is not limited to these examples. Abbreviations used below are as follows.
DA-1: 1,5-bis (4-aminophenoxy) pentane DA-2: 4,4'-diaminodiphenylmethane DA-3: 4,4'-diaminodiphenylamine CA-1: pyromellitic dianhydride CA- 2: 1,2,3,4-cyclobutanetetracarboxylic dianhydride CA-3: 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalene succinic dianhydride NMP: N- Methyl-2-pyrrolidone, GBL: γ-butyrolactone BCS: butyl cellosolve, PB: 1-butoxy-2-propanol DME: dipropylene glycol dimethyl ether DPM: dipropylene glycol monomethyl ether DAA: diacetone alcohol, DEDG: diethylene glycol diethyl ether DIBC: 2 , 6-Dimethyl-4-heptanol

<Measurement of viscosity>
The viscosities of polyamic acid and liquid crystal aligning agent were measured with an E-type viscometer (manufactured by Toki Sangyo Co., Ltd.) at 25 ° C.
<Measurement method of solid content concentration>
1.0 g of the solution was measured in an aluminum cup and subjected to heat treatment at 200 ° C. for 2 hours, then the amount of solid remaining on the cup was measured, and the solid content concentration of the solution was measured.

[Production of polyamic acid A1]
In a 2000 ml flask with a stirrer and a nitrogen inlet tube, 171.8 g of DA-1 was added, 1676 g of NMP was added, and the mixture was stirred and dissolved while feeding nitrogen. While stirring this diamine solution under water cooling, 113.8 g of CA-1 was added, NMP was further added so that the solid content concentration was 12% by weight, and the mixture was stirred for 20 hours while heating at 50 ° C. in a nitrogen atmosphere. A solution (viscosity: 90 mPa · s) of polyamic acid (A1) having a solid content concentration of 11.2% by weight was obtained.

[Production of polyamic acid A2]
In a 2000 ml flask with a stirrer and a nitrogen inlet tube, 100.8 g of DA-1 and 34.9 g of DA-5 were added, 1337 g of NMP was added, and the mixture was stirred and dissolved while feeding nitrogen. While stirring this diamine solution under water cooling, 92.2 g of CA-1 was added, NMP was further added so that the solid content concentration was 12% by weight, and the mixture was stirred for 20 hours while heating at 50 ° C. in a nitrogen atmosphere. A solution (viscosity: 520 mPa · s) of polyamic acid (A2) was obtained.

[Production of polyamic acid solution a1]
264.3 g of NMP and 200.0 g of BCS were added to 535.7 g of the polyamic acid (A1) solution to obtain a polyamic acid solution (a1) having an A1 concentration of 6.0% by weight.
[Production of polyamic acid solution a2]
264.3 g of NMP and 200.0 g of PB were added to 535.7 g of the polyamic acid (A1) solution to obtain a polyamic acid solution (a2) having an A1 concentration of 6.0% by weight.
[Production of polyamic acid solution a3]
264.3 g of NMP and 200.0 g of DIBC were added to 535.7 g of the polyamic acid (A1) solution to obtain a polyamic acid solution (a3) having an A1 concentration of 6.0% by weight.

[Production of polyamic acid B1]
Into a 2000 ml four-necked flask with a stirrer and a nitrogen inlet tube, 87.7 g of DA-3 was added, and 1052.5 g of a solvent (hereinafter referred to as solvent 1) in which NMP and GBL were blended at a ratio of 50% by weight was added. The mixture was stirred and dissolved while feeding nitrogen. While stirring this diamine solution under water cooling, 70.1 g of CA-2 and 382.7 g of solvent 1 were added, and the mixture was stirred under water cooling for 3 hours under a nitrogen atmosphere. Thereafter, 21.8 g of DA-2 and 191.3 g of solvent 1 were added and stirred. After DA-2 is dissolved, 33.0 g of CA-3 and 287.0 g of solvent 1 are added, and the mixture is stirred again for 3 hours under a nitrogen atmosphere under water cooling, so that the solid content concentration is 9.8 wt%. A solution (viscosity: 65 mPa · s) of polyamic acid (B1) was obtained. When 1.0 g of this polyamic acid (B1) solution was measured in an aluminum cup and treated at 200 ° C. for 2 hours, the solid content concentration was 9.8 wt%.

[Production of polyamic acid B2]
In a 2000 ml four-necked flask equipped with a stirrer and a nitrogen inlet tube, 95.6 g of DA-3, 18.2 g of DA-4, 967 g of NMP were added, and the mixture was stirred and dissolved while feeding nitrogen. While stirring this diamine solution under water cooling, 54.8 g of CA-2 and 276 g of NMP were added, and the mixture was stirred under water cooling for 3 hours under a nitrogen atmosphere. Thereafter, NMP was added to 75.0 g of CA-4 so that the solid concentration was 15% by weight, and the mixture was stirred for 12 hours while heating at 50 ° C. in a nitrogen atmosphere. This polyamic acid (B2) solution (viscosity: 302 mPa · s) was obtained.

[Example 1]
153.4 g of polyamic acid (B1) solution was measured, and 38.5 g of GBL solution containing 1.3 g of NMP and 1.3% by weight of 3-glycidoxypropyltriethoxysilane was added to the solution. .9g, PB78.5g and DIBC 50.0g were added and stirred at room temperature for 1 hour. Thereafter, 107.5 g of a2 was added, and the mixture was further stirred for 1 hour, whereby a solid content: NMP: GBL: PB: DIBC = 4.3: 30: 35.7: 20: 10 (% by weight) solution (C1 ) Was obtained.

[Example 2]
153.4 g of polyamic acid (B1) solution was measured, and 38.5 g of GBL solution containing 1.3% by weight of NMP and 1.3% by weight of 3-glycidoxypropyltriethoxysilane and 145 GBL were measured. .9 g and DIBC 53.5 g were added and stirred at room temperature for 1 hour. Thereafter, 107.5 g of a3 was added, and the mixture was further stirred for 1 hour, whereby a solution (C2) having a solid content: NMP: GBL: DIBC = 4.3: 30: 50.7: 15 (wt%) was added to 500. 0 g was obtained.

[Example 3]
153.4 g of polyamic acid (B1) solution was measured, and 38.5 g of GBL solution containing 1.3 g of NMP and 1.3% by weight of 3-glycidoxypropyltriethoxysilane was added to the solution. .9g, BCS 78.5g and DIBC 50.0g were added and stirred at room temperature for 1 hour. Thereafter, 107.5 g of a1 was added, and the mixture was further stirred for 1 hour, whereby a solid content: NMP: GBL: BCS: DIBC = 4.3: 30: 35.7: 20: 10 (% by weight) solution (C3 ) Was obtained.

[Example 4]
153.4 g of polyamic acid (B1) solution was measured, and 38.5 g of GBL solution containing 1.3 g of NMP and 1.3% by weight of 3-glycidoxypropyltriethoxysilane was added to the solution. .9 g, DIBC 53.5 g and DAA 50.0 g were added and stirred at room temperature for 1 hour. Thereafter, 107.5 g of a3 was added, and the mixture was further stirred for 1 hour, whereby a solid content: NMP: GBL: DIBC: DAA = 4.3: 30: 40.7: 15: 10 (% by weight) solution (C4 ) Was obtained.

[Example 5]
153.4 g of a polyamic acid (B1) solution was weighed, and 38.5 g of a GBL solution containing 1.3 g of NMP and 1.3% by weight of 3-glycidoxypropyltriethoxysilane was added to the solution. .9 g, DIBC 53.5 g and DEDG 25.0 g were added and stirred at room temperature for 1 hour. Thereafter, 107.5 g of a3 was added, and the mixture was further stirred for 1 hour, whereby a solid content: NMP: GBL: DIBC: DEDG = 4.3: 30: 40.7: 15: 5 (wt%) solution (C5 ) Was obtained.

[Example 6]
A mixture of 33.3 g of a 12 wt% polyamic acid (A2) solution and 106.6 g of a 15 wt% polyamic acid (B2) solution was stirred for 30 minutes, and then 11.1 g of NMP, -By adding 20.0 g of NMP solution containing 1.0% by weight of glycidoxypropyltriethoxysilane, 179.0 g of GBL, 75.0 g of DIBC and 75.0 g of BCS, and stirring at room temperature for 3 hours, A polymer (C11) having a polymer solid content ratio of A2 and B2 of 2: 8 and a solid content of NMP: GBL: DIBC: BCS = 4.2: 30: 40.8: 15: 15 (% by weight) is 500. 0.0 g was obtained.

[Example 7]
A mixed solution of 33.3 g of a 12% by weight polyamic acid (A2) solution and 106.6 g of a 15% by weight polyamic acid (B2) solution was stirred for 30 minutes. -20.0 g of NMP solution containing 1.0% by weight of glycidoxypropyltriethoxysilane, 6.0 g of NMP solution containing 10% by weight of AD-1, 179.0 g of GBL, 75.0 g of DIBC and By adding 75.0 g of BCS and stirring at room temperature for 3 hours, the polymer solid content ratio of A2 and B2 was 2: 8, and AD-1 was contained by 3.0% by weight with respect to the polymer solid content. 500.0 g of a solution (C12) having a total solid content: NMP: GBL: DIBC: BCS = 4.2: 30: 40.8: 15: 15 (% by weight) was obtained.

[Example 8]
A mixture of 33.3 g of a 12 wt% polyamic acid (A2) solution and 106.6 g of a 15 wt% polyamic acid (B2) solution was stirred for 30 minutes, and then 11.1 g of NMP, -By adding 20.0 g of NMP solution containing 1.0% by weight of glycidoxypropyltriethoxysilane, 179.0 g of GBL, 75.0 g of DIBC and 75.0 g of PB, and stirring at room temperature for 3 hours, A polymer (C13) having a polymer solid content ratio of A2 and B2 of 2: 8 and a solid content of NMP: GBL: DIBC: PB = 4.2: 30: 40.8: 15: 15 (% by weight) was 500. 0.0 g was obtained.

[Comparative Example 1]
153.4 g of polyamic acid (B1) solution was measured, and 38.5 g of GBL solution containing 1.3% by weight of NMP and 1.3% by weight of 3-glycidoxypropyltriethoxysilane and 145 GBL were measured. .9 g and 53.5 g of BCS were added and stirred at room temperature for 1 hour. Thereafter, 107.5 g of a1 was added, and the mixture was further stirred for 1 hour, whereby a solution (C6) having a solid content: NMP: GBL: BCS = 4.3: 30: 50.7: 15 (% by weight) of 500. 0 g was obtained.

[Comparative Example 2]
153.4 g of polyamic acid (B1) solution was measured, and 38.5 g of GBL solution containing 1.3 g of NMP and 1.3% by weight of 3-glycidoxypropyltriethoxysilane was added to the solution. .9 g, BCS 53.5 g and DPM 50.0 g were added and stirred at room temperature for 1 hour. Thereafter, 107.5 g of a1 was added, and the mixture was further stirred for 1 hour, whereby a solid content: NMP: GBL: BCS: DPM = 4.3: 30: 40.7: 15: 10 (wt%) solution (C7 ) Was obtained.

[Comparative Example 3]
153.4 g of polyamic acid (B1) solution was measured, and 38.5 g of GBL solution containing 1.3 g of NMP and 1.3% by weight of 3-glycidoxypropyltriethoxysilane was added to the solution. .9g and BCS 128.5g were added and stirred at room temperature for 1 hour. Thereafter, 107.5 g of a1 was added, and the mixture was further stirred for 1 hour, whereby a solution (C8) having a solid content: NMP: GBL: BCS = 4.3: 30: 35.7: 30 (% by weight) of 500. 0 g was obtained.

[Comparative Example 4]
153.4 g of polyamic acid (B1) solution was measured, and 38.5 g of GBL solution containing 1.3 g of NMP and 1.3% by weight of 3-glycidoxypropyltriethoxysilane was added to the solution. .9g, BCS 53.5g and DAA 50.0g were added and stirred at room temperature for 1 hour. Thereafter, 107.5 g of a1 was added, and the mixture was further stirred for 1 hour, whereby a solid content: NMP: GBL: BCS: DAA = 4.3: 30: 40.7: 15: 10 (% by weight) solution (C9 ) Was obtained.

[Comparative Example 5]
153.4 g of a polyamic acid (B1) solution was weighed, and 38.5 g of a GBL solution containing 1.3 g of NMP and 1.3% by weight of 3-glycidoxypropyltriethoxysilane was added to the solution. 9.9 g and 78.5 g of PB were added and stirred at room temperature for 1 hour. Thereafter, 107.5 g of a2 was added, and the mixture was further stirred for 1 hour, whereby a solution (C10) of solid content: NMP: GBL: PB = 4.3: 30: 45.7: 20 (% by weight) was added to 500. 0 g was obtained.

About Examples 1-8 and Comparative Examples 1-5, after filtering with a filter with a hole diameter of 1 micrometer, the viscosity in 25 degreeC was confirmed with the E-type viscosity meter (made by Toki Sangyo Co., Ltd.). Thereafter, the following coating evaluation was also performed.
[Inkjet applicability evaluation]
About the said Examples 1-8 and Comparative Examples 1-5, it apply | coated on the TFT substrate using the inkjet coating apparatus (made by Ishii notation company). The coating conditions were a nozzle pitch of 127 μm, a coating speed of 250 mm / sec, a dispensing amount of 70 pL, and a coating area of 36 × 36 mm. The film thickness of the coating film was applied on the condition of 120 nm when baked in an IR oven at 230 ° C. for 15 minutes after being temporarily dried on a 110 ° C. hot plate for 1 minute.

[Evaluation method of coating film]
The coating film obtained by temporarily drying the coated substrate at 110 ° C. was evaluated in four stages by comparing the degree of unevenness of dots and streaks generated due to the influence of contact holes and wiring. Lv4 is a material that can be visually confirmed to have a noticeable unevenness on the entire surface, Lv3 is a material that can be visually confirmed to be partially uneven, Lv2 is a material that cannot be seen visually, and Lv1 is an image that has no unevenness even on an optical microscope.
Moreover, it apply | coated also on the glass substrate by which chromium was vapor-deposited on the surface, the width | variety of the part with a color tone change (film thickness nonuniformity) of a coating-film edge part was measured with calipers, and it evaluated as Halo size. Note that the smaller the value of the Halo size, the better the coating film.
Furthermore, the coating film width was measured, and the difference between the measured value and the set value was evaluated as dimensional stability for the set application region. In this evaluation, the smaller the value, the better the coating film.
These results are shown in Tables 1 and 2.

  It should be noted that the entire contents of the specification, claims, drawings, and abstract of Japanese Patent Application No. 2006-072568 filed on March 31, 2016 are cited herein as disclosure of the specification of the present invention. Incorporate.

Claims (12)

A liquid crystal aligning agent comprising: a polymer having an ability to align liquid crystals; and a solvent containing a compound represented by the following formula (a).

In formula (a), R _{1 and} R ₂ are each independently a linear or branched alkyl group having 1 to 8 carbon atoms. However, the total number of carbon atoms of R ₁ and R ₂ is 4 or more.   2. The polymer according to claim 1, wherein the polymer is at least one polymer selected from the group consisting of a polyimide precursor obtained by a reaction between a tetracarboxylic acid derivative component and a diamine component and a polyimide that is an imidized product thereof. Liquid crystal aligning agent.   The liquid crystal aligning agent of Claim 1 or 2 in which the said solvent contains 1 to 50weight% of the total amount of solvent. The liquid crystal aligning agent according to any one of claims 1 to 3, wherein the solvent is at least one selected from the group consisting of the following a-1 to a-48.

  The solvent is the a-22, a-13 to a-21, a-24, a-26, a-27, a-31, a-34, a-37, or a-38. Liquid crystal aligning agent as described in.   The liquid crystal aligning agent according to claim 4, wherein the solvent is the a-22 or a-38.   The solvent further comprises N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, γ-butyrolactone, 3-methoxy-N, N-dimethylpropanamide and 1,3-dimethyl-2-imidazolidinone. The liquid crystal aligning agent of any one of Claims 1-6 containing the at least 1 sort (s) of good solvent chosen from a group.   The liquid crystal aligning agent of Claim 7 in which the said good solvent contains 5-30 weight part with respect to 100 weight part of said specific solvent.   As a solvent, butyl cellosolve, 1-butoxy-2-propanol, butyl cellosolve acetate, dipropylene glycol monomethyl ether, diacetone alcohol, diethylene glycol diethyl ether, diisopentyl ether, propylene glycol diacetate, diisobutyl ketone, ethyl carbitol The liquid crystal aligning agent of any one of Claims 1-8 containing the at least 1 sort (s) of poor solvent chosen from the group which consists of dipropylene glycol dimethyl ether.   The liquid crystal aligning agent of Claim 9 with which the said poor solvent contains 5-40 weight part with respect to 100 weight part of said specific solvent.   The liquid crystal aligning film obtained from the liquid crystal aligning agent of Claims 1-10.   A liquid crystal display device comprising the liquid crystal alignment film according to claim 11.